Compaction rollers and wheels used on landfill operations and particularly sanitary landfill operations are equipped generally with cleats or feet of the type for grinding and crushing materials to reduce the size and bulk of the material. As shown in the assignee's prior patents, U.S. Pat. Nos. 3,922,106 and 4,919,566, an earth and sanitary fill compaction roller has been shown employing two different types of feet having a replaceable wear cap as a part of the cleat assemblies. The wear caps are welded to a base portion of the assembly, which in turn is welded to the roller as shown in U.S. Pat. No. 3,922,106. The wear caps in U.S. Pat. No. 4,919,566 are readily removable from the base portion of the assembly using common tools available at the job site. It has been observed that due in large degree to manufacturing tolerances that the use of removable wear caps coupled to a fixed base, in severe service exposes the assembly to twisting forces which in time materially reduce the service life of the wear cap and cleat assembly. In the '566 patent, a cleat assembly was disclosed including means for restraining twisting of the wear cap relative to the base, which function entirely satisfactory with compaction equipment then operating in the 70,000 lbs. gross weight class. Improvements in the cleat assembly are desired for use on compaction rollers mounted on compaction machines now furnished in the 100,000 to 120,000 lbs gross vehicular weight class.
More particularly, the compaction vehicles of the higher operating weights now coming into service apply substantially more torque to the compaction rollers via their larger engines and transmissions than was the case with compactors that were 30,000 to 50,000 lbs. lighter in gross vehicle weight. Moreover, landfill operators expect very long service life of the compaction rollers and cleat assemblies, some required assurances that these components will render a service life on the order of 20,000 hours. Thus, it is highly desirable to accommodate in the cleat assemblies on the compaction rollers the higher torque than tractive forces applied by the extra heavy duty compaction machinery now entering into service.